1. Technical Field of the Invention
This invention relates to radio telecommunication systems and, more particularly, to a method of providing status information regarding activated services to subscribers of a cellular telecommunications network.
2. Description of Related Art
In modem cellular telecommunication networks, the networks are divided into cells which service a defined area for mobile stations. Each cell contains a base station which transmits and receives voice and control information to and from mobile stations (mobile phones) which are located within the cell's coverage area. Each of the cells employs a separate control channel for relaying control information to mobile stations, and voice channels for relaying voice information.
The control channel, whether analog or digital, performs the function of providing access for mobile subscribers to services provided by cells within a cellular telecommunications network. Analog control channels are described in the Advanced Mobile Telephone Service (AMPS) or IS-553 analog air interface specification which is hereby incorporated by reference herein. The current version of the cellular industry standard for a Digital Control Channel (DCCH) is described in Project No. 3011-2 of the EIA/TIA Interim Standard IS-54-C, "Cellular System Dual-Mode Mobile Station--Base Station Compatibility Standard", dated Apr. 8, 1994. The IS-54-C specification comprises two distinct parts:
IS-54.1--This part specifies the operation of the digital control channel and is organized in accordance with the general concept of protocol layering; and PA1 IS-54.2--This part specifies the modified operation of the analog control channel and traffic channels required in support of new functionality, such as short message service (SMS) operation.
The IS-54-C specification, including IS-54.1 and IS-54.2, is hereby incorporated by reference herein.
Today's standards offer mobile telephone subscribers a great deal of flexibility in transferring calls to other numbers. For example, a subscriber may transfer a call to fixed number services, variable number services, or voice mail transfer services. Each of these call-transfer services has a different priority, thus allowing subscribers to assign different forward-to numbers (C-numbers) to different call-transfer services, depending on the priority they desire.
Flexibility, however, also results in complexity in existing cellular telephone systems. In addition to assigning a call-transfer service for each C-number, subscribers must also individually activate or deactivate each call-transfer service. Many subscribers may forget the current state of their call-transfer services (i.e., whether a particular call-transfer service has a C-number assigned; if so, which C-number is assigned; and whether the call-transfer service is activated or deactivated). To obtain status information of call-transfer services, subscribers must call their telephone service provider and request an agent to access their profile and tell them the current status. Instead, subscribers sometimes try to guess the current state, and if a subscriber guesses wrong, calls may be missed or routed to the wrong C-number.
Although there are no known prior art teachings of a solution to the aforementioned deficiency and shortcoming such as that disclosed herein, a number of prior art references exist that discuss subject matter that bears some relation to matters discussed herein. Such prior art references are U.S. Pat. No. 5,181,239 to Jolissaint, and U.S. Pat. No. 5,043,983 to Dorst et al. Each of these references is discussed briefly below.
U.S. Pat. No. 5,181,239 to Jolissaint (Jolissaint) discloses a method and apparatus in a wireline telephone system which maintains a database record relating to a caller at a switching machine. Portions of the caller information may be visually displayed to agents on display telephones attached to the switch. However, Jolissaint does not in any way teach or suggest a method by which a caller may access and retrieve his caller-related information and display such information on the caller's own telephone. In addition, Jolissaint is limited to a wireline telephone system, and does not suggest how such a method could be implemented in a cellular telephone system.
U.S. Pat. No. 5,043,983 to Dorst et al. (Dorst) discloses a system in which an intelligent telephone is connected to a central telephone office over an integrated services digital network (ISDN) basic rate interface (BRI). At the conclusion of an operator-assisted call, a data block comprising time and charges information is sent over the BRI to the intelligent telephone. The telephone then displays this information on a visual display to the caller. Dorst, however, is limited to a wireline telephone system, and does not suggest how such a system could be implemented in a cellular telephone system. In addition, Dorst does not teach or suggest any method of retrieving other caller information such as the status of call-transfer services, as disclosed herein.
Review of each of the foregoing references reveals no disclosure or suggestion of a method such as that described and claimed herein.
It would be a distinct advantage to have a method in a cellular telephone network for displaying on a subscriber's mobile telephone display, the current status of the subscriber's telephone services. Such a method would enable the subscriber to display, upon registration and upon demand, the services that are currently active, and, in the case of call-transfer services, the C-numbers assigned to each service. This relieves the subscriber of the burden of having to remember the status of his/her services, and reduces the possibility of calls being missed or routed to the wrong C-number. The present invention provides such a method.